In-cell touch panel, touch detection method and liquid crystal display device

ABSTRACT

Disclosed are an in-cell touch panel, a touch detection method and a liquid crystal display device. The in-cell touch panel includes a driving layer, a liquid crystal layer and a sensing layer which are sequentially stacked, and a touch control unit and an LCD driving unit which are connected to each other, the driving layer being provided with a plurality of driving lines, the sensing layer being provided with a plurality of sensing lines connected to the touch control unit. The driving layer includes at least two scanning regions, and the touch control unit is configured to send at least two driving signals with different frequencies to scan corresponding scanning regions on the driving layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of international applicationNo. PCT/CN2015/077426, filed on Apr. 24, 2015, which claims priority toChinese Patent Application No. 201410705573.4, filed on Nov. 27, 2014,both of which are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to the technical field of liquid crystaldisplays, and in particular, relates to an in-cell touch panel, a touchdetection method and a liquid crystal display device.

BACKGROUND

The in-cell technology is a method for embedding functions of a touchpanel to liquid crystal pixels. That is, functions of a touch sensor areembedded inside a display screen. Both touch control and display controlare implemented by means of cooperation of a liquid crystal display(LCD) driving unit and a touch control unit.

To implement the touch control and display functions on an in-cell touchpanel, the touch control unit needs to constantly scan the screen. Thescanning process in the related art is as follows: the LCD driving unitsends a scanning start timing signal and a scanning timing signal to thetouch control unit; the touch control unit sends a driving signal havinga fixed time length and a fixed frequency to the LCD driving unit at atimeslot when the scanning timing signal is a high level; the LCDdriving unit outputs the driving signal to a driving line on the drivinglayer of the screen to implement scanning of the screen and to finallyimplement the touch control function; and the LCD driving unit displaysa scanning result at the timeslot when the scanning timing signal is alow level to implement the display function.

However, with increase of the screen size, the number of driving linesmay be increased. While ensuring the report rate and the LCD display,the time of scanning the driving layer needs to be shortened. That is,the time when the scanning timing signal given each time is a high levelneeds to be reduced, such that the signal-to-noise ratio of the touchcontrol unit is reduced and the touch control performance is affected.In addition, with improvement of the screen resolution, the time of theLCD display is increased. That is, the time when the scanning timingsignal given each time is a low level is increased and the time when thescanning timing signal is a high level is reduced. In this way, the timeof scanning the driving layer is shortened, such that thesignal-to-noise ratio of the touch control unit is reduced and the touchcontrol performance is affected.

SUMMARY

The present invention is intended to provide an in-cell touch panel, atouch control detection method and a liquid crystal display device, inorder to solve the above problem, improve the signal-to-noise ratio andenhance the touch control performance.

The present invention provides an in-cell touch panel, including adriving layer, a liquid crystal layer and a sensing layer which aresequentially stacked, and a touch control unit and an LCD driving unitwhich are connected to each other, the driving layer being provided witha plurality of driving lines, the sensing layer being provided with aplurality of sensing lines connected to the touch control unit; thedriving layer includes at least two scanning regions, and the touchcontrol unit is configured to send at least two driving signals withdifferent frequencies to scan corresponding scanning regions on thedriving layer.

The present invention also provides a touch detection method, including:

defining at least two scanning regions at a driving layer of an in-celltouch panel, wherein the driving layer comprises a plurality of drivinglines; and

sending, by a touch control unit, at least two driving signals withdifferent frequencies to scan corresponding scanning regions on thedriving layer, wherein a plurality of sensing lines of a sensing layerof the in-cell touch panel are connected to the touch control unit.

The present invention further provides a liquid crystal display device,including an in-cell touch panel and a touch control unit and an LCDdriving unit which are connected to each other, wherein the in-celltouch panel includes a driving layer, a liquid crystal layer and asensing layer which are sequentially stacked, the driving layer beingprovided with a driving line, the sensing layer being provided with asensing line connected to the touch control unit; wherein the drivinglayer includes at least two scanning regions, and the touch control unitis configured to send at least two driving signals with differentfrequencies to scan corresponding scanning regions on the driving layer.

In the in-cell touch panel according to the present invention, at leasttwo scanning regions are defined on a driving layer, and a touch controlunit sends at least two driving signals with different frequencies, suchthat the at least two scanning regions may be simultaneously scanned byusing the at least two driving signals with different frequencies.Through such multi-frequency scanning, with the same scanning timing,more driving lines are supported, and thus a larger screen is supported;with the same screen size, a shorter driving time is supported, and thusmore display time is provided for the LCD and it is favorable toimproving the resolution of the screen; and with the same screen sizeand the same resolution, more coding time is used, and thus thesignal-to-noise ratio of the touch control unit is effectively improvedand the touch control performance is enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an in-cell touch panel according to afirst embodiment of the present invention;

FIG. 2 is a schematic diagram of connection between an LCD driving unitand a driving layer according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a diving layer according to anembodiment of the present invention;

FIG. 4 is a schematic diagram of connection between a touch control unitand a sensing layer according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of signal transmission between an LCDdriving unit and a touch control unit according to an embodiment of thepresent invention;

FIG. 6 is a schematic diagram of a scanning start timing signal and ascanning timing signal according to an embodiment of the presentinvention;

FIG. 7 is a schematic diagram of modules of a touch control unitaccording to an embodiment of the present invention;

FIG. 8 is a schematic diagram of an in-cell touch panel according to asecond embodiment of the present invention; and

FIG. 9 is a flowchart of a touch detection method according to anembodiment of the present invention.

The attainment of the objectives, functional features and advantages ofthe present invention are further described hereinafter with referenceto the specific embodiments and the accompanying drawings.

DETAILED DESCRIPTION

It should be understood that the embodiments described here are onlyexemplary ones for illustrating the present invention, and are notintended to limit the present invention.

Referring to FIG. 1, a first embodiment of the present inventionprovides an in-cell touch panel. The in-cell touch panel includes adriving layer, a liquid crystal layer and a sensing layer which aresequentially stacked, and a touch control unit and an LCD driving unitwhich are connected to each other. The driving layer is connected to theLCD driving unit, and the sensing layer is connected to the touchcontrol unit. The LCD driving unit is preferably an LCD drivingintegrated circuit (IC) or an LCD driving chip, and the touch controlunit is preferably a touch control IC or a touch control chip.

As illustrated in FIG. 2, a driving layer 10 is provided with drivinglines 11, the LCD driving unit is connected to the driving lines 11; thedriving layer 10 includes at least two scanning regions, which are, forexample, a scanning region A and a scanning region B according to thisembodiment. In FIG. 2, an upper portion is the scanning region A and alower portion is the scanning region B. The number of scanning regionson the driving layer and the partitioning of the scanning regions arenot limited. For example, as illustrated in FIG. 3, the scanning regionA and the scanning region B may also be arranged in a staggering manner.As illustrated in FIG. 4, a sensing layer 20 is provided with a sensingline 21, and a sensing channel of the touch control unit is connected tothe sensing line 21. The touch control unit is configured to send atleast two driving signals with different frequencies to scancorresponding scanning regions on the driving layer 10.

Specifically, as illustrated in FIG. 5 and FIG. 6, the LCD driving unitsends a scanning timing signal and a scanning start timing signal to thetouch control unit, wherein the scanning timing signal can be used tocontrol the touch control unit to perform scanning, and the scanningstart timing signal indicates start of scanning. A raising edge or afalling edge of the scanning start timing signal indicates start of thescanning activity of a current frame. Upon receiving the scanning timingsignal and the scanning start timing signal, the touch control unitsynchronizes the scanning start timing signal and the scanning timingsignal, and send at least two driving signals with different frequenciesto the LCD driving unit at a timeslot when the scanning timing signal isa first level, for example, a driving signal 1 and a driving signal 2with different frequencies in this embodiment. Upon receiving thedriving signals, the LCD driving unit amplifies the driving signals andoutputs the amplified driving signals with different frequencies todriving lines in the corresponding scanning regions on the drivinglayer, for example, outputting the driving signal 1 to the data lines inthe scanning region A and outputting the driving signal 2 to the datalines in the scanning region B, to simultaneously scan the scanningregion A and the scanning region B. In addition, the LCD driving unitfurther displays a scanning result at a timeslot when the scanningtiming signal is a second level. That is, the timeslot when the scanningtiming signal is the first level is the time for scanning the drivinglayer by the touch control unit, and the timeslot when the scanningtiming signal is the second level is the time for displaying thescanning result by the LCD driving unit, that is, the liquid crystaldisplay time.

The first level may be a high level or a low level, and correspondingly,the second level may be a low level or a high level; that is, when thefirst level is a high level, the second level is a low level, and whenthe first level is a low level, the second level is a high level. Asillustrated in FIG. 6, in this embodiment, the timeslot when thescanning timing signal is the high level is the time for scanning thedriving layer by the touch control unit, and the timeslot when thescanning timing signal is the low level is the time for displaying thescanning result by the LCD driving unit, that is, the liquid crystaldisplay time.

Further, as illustrated in FIG. 7, the touch control unit furtherincludes at least two frequency demodulation modules, for example, afrequency demodulation module 1 and a frequency demodulation module 2 inthis embodiment. The touch control unit detects a touch control signalvia a sensing channel, wherein the touch control signal is a drivingsignal which is changed after a user performs a touch control operation.Since the driving signals in different scanning regions have differentfrequencies, the touch control signals with corresponding frequenciesneed to be demodulated by using corresponding frequency demodulationmodules, and then the demodulated touch control signals need to be sentto the corresponding modules for processing. In this way, the functionof touch sensing is implemented.

Referring to FIG. 8, a second embodiment of the present inventionprovides an in-cell touch panel. This embodiment differs from the firstembodiment in that the touch control unit is connected to the sensingline on the sensing layer and the driving lines on the driving layerrespectively, and the touch control unit directly outputs at least twodriving signals with different frequencies to driving lines in thecorresponding scanning regions on the driving layer. As such, thecircuit structure can be simplified.

In the in-cell touch panel according to the present invention, at leasttwo scanning regions are defined at a driving layer, and a touch controlunit sends at least two driving signals with different frequencies, suchthat the at least two scanning regions may be simultaneously scanned byusing the at least two driving signals with different frequencies.Through such multi-frequency scanning, with the same scanning timing,more driving lines are supported, and thus a larger screen is supported;with the same screen size, a shorter driving time is supported, and thusmore display time is provided for the LCD and it is favorable toimproving the resolution of the screen; and with the same screen sizeand the same resolution, more coding time is used, and thus thesignal-to-noise ratio of the touch control unit is effectively improved.

Referring to FIG. 9, an embodiment of the present invention provides atouch detection method, wherein the touch detection method includes thefollowing steps:

Step S10: At least two scanning regions are defined on a driving layer.

As illustrated in FIG. 2 and FIG. 3, a scanning region A and a scanningregion B may be defined on the driving layer, wherein both the scanningregion A and the scanning region B have at least one driving line.

Step S11: A touch control unit sends at least two driving signals withdifferent frequencies to scan corresponding scanning regions on thedriving layer.

Optionally, the touch control unit may firstly send at least two drivingsignals with different frequencies, for example, a driving signal 1 anda driving signal 2. Upon receiving the driving signals, the LCD drivingunit amplifies the driving signals, and finally outputs the drivingsignals with different frequencies to driving lines in the correspondingscanning regions on the driving layer to scan the corresponding scanningregions, for example, outputting the driving signal 1 to a driving linein the scanning region A and outputting the driving signal 2 to adriving line in the scanning region B.

Preferably, the touch control unit may directly output the at least twodriving signals with different frequencies to driving lines in thecorresponding scanning regions on the driving layer, to scan thecorresponding scanning regions.

In addition, the touch control unit detects a touch control signal via asensing channel, wherein the touch control signal is a driving signalwhich is changed after a user performs a touch control operation. Sincethe driving signals in different scanning regions have differentfrequencies, the touch control signals with corresponding frequenciesneed to be demodulated by using corresponding frequency demodulationmodules, and then the demodulated touch control signals need to be sentto the corresponding modules for processing. In this way, the functionof touch sensing is implemented.

In addition, in this embodiment, the LCD driving unit sends a scanningtiming signal and a scanning start timing signal to the touch controlunit; the touch control unit sends a driving signal for scanning at atimeslot when the scanning timing signal is a first level; and the LCDdriving unit displays a scanning result at a timeslot when the scanningtiming signal is a second level. The first level may be a high level ora low level, and correspondingly, the second level may be a low level ora high level; that is, when the first level is a high level, the secondlevel is a low level, and when the first level is a low level, thesecond level is a high level.

With the touch detection method according to the present invention, atleast two scanning regions are defined on a driving layer, and a touchcontrol unit sends at least two driving signals with differentfrequencies, such that the at least two scanning regions may besimultaneously scanned by using the at least two driving signals withdifferent frequencies. Through such multi-frequency scanning, with thesame scanning timing, more driving lines are supported, and thus alarger screen is supported; with the same screen size, a shorter drivingtime is supported, and thus more display time is provided for the LCDand it is favorable to improving the resolution of the screen; and withthe same screen size and the same resolution, more coding time is used,and thus the signal-to-noise ratio of the touch control unit iseffectively improved.

It should be noted that the in-cell touch panel provided in the aboveembodiment is based on the same inventive concept as the touch detectionmethod embodiment, and the technical features in the apparatusembodiments are correspondingly applicable to the method embodiments,which are thus not described herein any further.

The present invention further provides a liquid crystal display device,comprising an in-cell touch panel, wherein the in-cell touch panelcomprises a driving layer, a liquid crystal layer and a sensing layerwhich are sequentially stacked, and a touch control unit and an LCDdriving unit which are connected to each other, the driving layer beingprovided with a driving line, the sensing layer being provided with asensing line connected to the touch control unit; wherein the drivinglayer comprises at least two scanning regions, and the touch controlunit is configured to send at least two driving signals with differentfrequencies to scan corresponding scanning regions on the driving layer.The in-cell touch panel described in this embodiment is the in-celltouch panel involved in the above embodiment of the present invention,which is thus not described herein any further.

In the liquid crystal display device according to the present invention,at least two scanning regions are defined on a driving layer, and atouch control unit sends at least two driving signals with differentfrequencies, such that the at least two scanning regions may besimultaneously scanned by using the at least two driving signals withdifferent frequencies. Through such multi-frequency scanning, with thesame scanning timing, more driving lines are supported, and thus alarger screen is supported; with the same screen size, a shorter drivingtime is supported, and thus more display time is provided for the LCDand it is favorable to improving the resolution of the screen; and withthe same screen size and the same resolution, more coding time is used,and thus the signal-to-noise ratio of the touch control unit iseffectively improved.

The above embodiments illustratively describe two driving signals withdifferent frequencies and two scanning regions as an example. Inpractice, more than two driving signals with different frequencies andmore than two scanning regions may also be used.

It should be understood that described above are merely exemplaryembodiments of the present invention, but are not intended to limit thescope of the present invention. Any equivalent structure or equivalentprocess variation made based on the specification and drawings of thepresent invention, which is directly or indirectly applied in otherrelated technical fields, fall within the scope of the presentinvention.

In the in-cell touch panel according to the present invention, at leasttwo scanning regions are defined on a driving layer, and a touch controlunit sends at least two driving signals with different frequencies, suchthat the at least two scanning regions may be simultaneously scanned byusing the at least two driving signals with different frequencies.Through such multi-frequency scanning, with the same scanning timing,more driving lines are supported, and thus a larger screen is supported;with the same screen size, a shorter driving time is supported, and thusmore display time is provided for the LCD and it is favorable toimproving the resolution of the screen; and with the same screen sizeand the same resolution, more coding time is used, and thus thesignal-to-noise ratio of the touch control unit is effectively improved.

What is claimed is:
 1. An in-cell touch panel, comprising a drivinglayer, a liquid crystal layer and a sensing layer which are sequentiallystacked, and a touch control unit and an LCD driving unit which areconnected to each other, the driving layer being provided with aplurality of driving lines, the sensing layer being provided with aplurality of sensing lines connected to the touch control unit; whereinthe driving layer comprises at least two scanning regions, and the touchcontrol unit is configured to send at least two driving signals withdifferent frequencies to scan corresponding scanning regions on thedriving layer.
 2. The in-cell touch panel according to claim 1, whereinthe driving lines are connected to the LCD driving unit, the touchcontrol unit is configured to send at least two driving signals withdifferent frequencies to the LCD driving unit; and the LCD driving unitis configured to amplify the at least two driving signals with differentfrequencies and output the amplified driving signals to the drivinglines in the corresponding scanning regions on the driving layer.
 3. Thein-cell touch panel according to claim 2, wherein the LCD driving unitis configured to send a scanning timing signal and a scanning starttiming signal to the touch control unit.
 4. The in-cell touch panelaccording to claim 3, wherein the touch control unit is configured tosend the driving signals for scanning at a timeslot when the scanningtiming signal is a first level, and the LCD driving unit is furtherconfigured to display a scanning result at a timeslot when the scanningtiming signal is a second level.
 5. The in-cell touch panel according toclaim 1, wherein the driving line are connected to the touch controlunit, and the touch control unit is configured to directly output atleast two driving signals with different frequencies to the drivinglines in the corresponding scanning regions on the driving layer.
 6. Thein-cell touch panel according to claim 1, wherein the touch control unitcomprises at least two frequency demodulation modules; and the touchcontrol unit is further configured to detect a touch control signal anddemodulate the touch control signal by using a corresponding frequencydemodulation module.
 7. A touch control detection method, comprising:defining at least two scanning regions on a driving layer of an in-celltouch panel, wherein the driving layer comprises a plurality of drivinglines; and sending, by a touch control unit, at least two drivingsignals with different frequencies to scan corresponding scanningregions on the driving layer, wherein a plurality of sensing lines of asensing layer of the in-cell touch panel are connected to the touchcontrol unit.
 8. The touch control detection method according to claim7, wherein the sending, by a touch control unit, at least two drivingsignals with different frequencies to scan corresponding scanningregions on the driving layer comprises: sending, by the touch controlunit, at least two driving signals with different frequencies to the LCDdriving unit; and amplifying, by an LCD driving unit, the at least twodriving signals with different frequencies, and outputting the amplifieddriving signals to driving lines in the corresponding scanning regionson the driving layer, to scan the corresponding scanning regions.
 9. Thetouch control detection method according to claim 7, wherein thesending, by a touch control unit, at least two driving signals withdifferent frequencies to scan corresponding scanning regions on thedriving layer comprises: directly outputting, by the touch control unit,the at least two driving signals with different frequencies to drivinglines in the corresponding scanning regions on the driving layer, toscan the corresponding scanning regions.
 10. The touch control detectionmethod according to claim 7, further comprising: detecting a touchcontrol signal, and demodulating the touch control signal by using acorresponding frequency demodulation module.
 11. The touch controldetection method according to claim 7, further comprising: sending, byan LCD driving unit, a scanning timing signal and a scanning starttiming signal to the touch control unit; and sending, by the touchcontrol unit, a driving signal for scanning at a timeslot when thescanning timing signal is a first level; and displaying, by the LCDdriving unit, a scanning result at a timeslot when the scanning timingsignal is a second level.
 12. A liquid crystal display device,comprising a driving layer comprising at least two scanning regionswhich comprises a plurality of driving lines respectively; a liquidcrystal layer; a touch control unit; an LCD driving unit connected tothe touch control unit; and a sensing layer comprising a plurality ofsensing lines connected to the touch control unit, wherein the drivinglayer, the liquid crystal layer and the sensing layer are sequentiallystacked, and the touch control unit is configured to send at least twodriving signals with different frequencies to scan correspondingscanning regions on the driving layer.
 13. The liquid crystal displaydevice according to claim 12, wherein the driving lines are connected tothe LCD driving unit, the touch control unit is configured to send theat least two driving signals with different frequencies to the LCDdriving unit, and the LCD driving unit is configured to amplify the atleast two driving signals with different frequencies and output theamplified driving signals to the driving lines in the correspondingscanning regions.
 14. The liquid crystal display device according toclaim 12, wherein the driving lines are connected to the touch controlunit, and the touch control unit is configured to directly output the atleast two driving signals with different frequencies to the drivinglines in the corresponding scanning regions.
 15. The liquid crystaldisplay device according to claim 12, wherein the touch control unitcomprises at least two frequency demodulation modules and the touchcontrol unit is further configured to detect a touch control signal anddemodulate the touch control signal by using a corresponding frequencydemodulation module.
 16. The liquid crystal display device according toclaim 12, wherein the LCD driving unit is configured to send a scanningtiming signal and a scanning start timing signal to the touch controlunit.
 17. The liquid crystal display device according to claim 16,wherein the touch control unit is configured to send the driving signalsfor scanning at a timeslot when the scanning timing signal is a firstlevel, and the LCD driving unit is further configured to display ascanning result at a timeslot when the scanning timing signal is asecond level.